The present invention relates to a wiper system which can increase a wiping area on a glass surface with a simple construction.
A conventional wiper system has a link mechanism provided between a wiper motor and a wiper arm (for example, refer to Patent Literature No. 1).
[Patent Literature No. 1]
The Unexamined Japanese Patent Application No. Heil-229747 (FIGS. 2A and 2B on page 3)
Referring to the drawings, Patent Literature No. 1 will be described in detail below.
FIGS. 8A and 8B are explanatory views explaining a conventional vehicle wiper system (FIGS. 8A and 8B represent, respectively, a copy of FIGS. 2A and 2B attached to Patent Literature No. 1).
In FIG. 8A, the conventional vehicle wiper system is constructed such that an oscillating arm 400 and a guide arm 800, which are both provided outside a vehicle body, are coupled together via a link mechanism 200 provided inside the vehicle body, one end of the oscillating arm 400 is supported by a support shaft 300 which is rotatably fitted in the vehicle body, and a main wiper arm 500 is rotatably supported at the other end of the oscillating arm 400 by means of a rivet 350. In addition, the wiper system is constructed such that one end of the guide arm 800 is supported by a support shaft 700 which is rotatably fitted in the vehicle body, the main wiper arm 500 is rotatably supported at the other end of the guide arm 800 by means of a rivet 740, a wiper blade, which is not shown, is attached to a distal end of the main wiper arm 500, one end of an auxiliary wiper arm 900 is coupled to the wiper blade via a support stay, and the other end of the auxiliary wiper arm 900 is coupled to the other end of the oscillating arm 400.
In FIG. 8B, the link mechanism 200 provided inside the vehicle body includes substantially V-shaped arms 201, 202 and an output lever 205 and is coupled to a direct-current d-rive motor 100 via a drive arm 102 and a rotating arm 101.
The operation of the wiper system constructed as is described heretofore will briefly be described. Firstly, when the direct-current drive motor 100 rotates in a direction indicated by an arrow X, the drive arm 102 moves, and the output lever 205 rotates in a direction indicated by an arrow Y, whereby the oscillating arm 400 revolves, and the main wiper 500 also revolves. Then, when the rotating arm 101 rotates half a revolution (180°) or more, the main wiper 500 starts to return.
In the vehicle wiper system shown in FIGS. 8A and 8B, components are required which include the oscillating arm 400 and the guide arm 800 which turn the main wiper arm 500, the support shafts 300, 700 which accompany the oscillating arm 400 and the guide arm 800, respectively, and the output lever 205, whereby the construction of the wiper system becomes complex, the number of components in the wiper system is increased, and eventually the production costs is increased.
In addition, in the conventional vehicle wiper system, there are provided a number of coupling portions where the oscillating arm, the guide arm 800 and the output lever 205 are coupled rotatably, whereby sources are increased where wear and noise, which are inherent in those coupling portions, are caused.